Method for producing organic electroluminescent device

Abstract

A method for producing an organic electroluminescent device (100) includes the step of forming a driving circuit layer (2) on a substrate (1); the step of forming an inorganic protective layer (Pa) on the driving circuit layer; the step of forming an organic flattening layer (Pb) on the inorganic protective layer; the step of heating the organic flattening layer to a temperature higher than, or equal to, 200° C.; the step of forming an organic electroluminescent element layer (3) on the organic flattening layer after the step of heating; and, after the organic flattening layer is formed but before the organic flattening layer is heated, the step of forming an organic polymer film covering the organic flattening layer and the step of removing the organic polymer film.

The invention claimed is: 
     
       1. A method for producing an organic electroluminescent device, the organic electroluminescent device including a substrate; a driving circuit layer including a plurality of TFTs formed on the substrate, a plurality of gate bus lines and a plurality of source bus lines each connected with either one of the plurality of TFTs, a plurality of terminals, and a plurality of lead wires connecting each of the plurality of terminals with either one of the plurality of gate bus lines or either one of the plurality of source bus lines; an inorganic protective layer formed on the driving circuit layer and exposing at least the plurality of terminals; an organic flattening layer formed on the inorganic protective layer; an organic electroluminescent element layer formed on the organic flattening layer and including a plurality of organic electroluminescent elements each connected with either one of the plurality of TFTs; and a thin film encapsulation structure formed to cover the organic electroluminescent element layer;
 the method comprising: 
 step A of forming the driving circuit layer on the substrate; 
 step B of forming the inorganic protective layer on the driving circuit layer; 
 step C of forming the organic flattening layer on the inorganic protective layer; 
 step D of heating the organic flattening layer to a temperature higher than, or equal to, 200° C.; 
 step E of forming the organic electroluminescent element layer on the organic flattening layer after the step of heating; and 
 step C 1  of forming an organic polymer film covering the organic flattening layer and step C 2  of removing the organic polymer film, the step C 1  and the step C 2  being performed after the step C but before the step D. 
 
     
     
       2. The method according to  claim 1 , further comprising the step of storing or transporting the substrate having the organic polymer film formed thereon between the step C 1  and the step C 2 . 
     
     
       3. The method according to  claim 1 , wherein the step C 1  includes the step of supplying a solution of the organic polymer film onto the organic flattening layer. 
     
     
       4. The method according to  claim 1 , wherein the organic polymer film is formed of a water-soluble polymer. 
     
     
       5. The method according to  claim 4 , wherein the step C 2  includes the step of dissolving the organic polymer film in an aqueous solvent. 
     
     
       6. The method according to  claim 4 , wherein the water-soluble polymer is poly(vinyl alcohol). 
     
     
       7. The method according to  claim 1 , wherein the organic flattening layer is formed of a photosensitive resin. 
     
     
       8. The method according to  claim 1 , wherein the organic flattening layer is formed of polyimide. 
     
     
       9. The method according to  claim 1 , wherein as seen in a direction of normal to the substrate, the organic flattening layer is formed in a region where the inorganic protective layer is formed, the plurality of organic electroluminescent elements are formed in a region where the organic flattening layer is formed, and an outer perimeter of the thin film encapsulation structure crosses the plurality of lead wires and is present between an outer perimeter of the organic flattening layer and an outer perimeter of the inorganic protective layer;
 the thin film encapsulation structure comprises a first inorganic barrier layer formed on the organic electroluminescent element layer, an organic barrier layer formed on the first inorganic barrier layer, and a second inorganic barrier layer formed on the organic barrier layer; and 
 in a region where the inorganic protective layer and the first inorganic barrier layer are in direct contact with each other on the plurality of lead wires, a tapering angle of a side surface of a cross-section of the first inorganic barrier layer taken along a plane parallel to a width direction of the plurality of lead wires is smaller than 90 degrees. 
 
     
     
       10. The method according to  claim 9 , wherein the tapering angle of the side surface of the first inorganic barrier layer is smaller than 70 degrees. 
     
     
       11. The method according to  claim 9 , further comprising:
 step F of, after the step E, forming the first inorganic barrier layer selectively in an active region where the plurality of organic electroluminescent elements are formed; 
 step G of, after the step F, locating the substrate in a chamber and supplying a vapor-like or mist-like photocurable resin into the chamber; 
 step H of condensing the photocurable resin on the first inorganic barrier layer such that the photocurable resin is not present on a part of the first inorganic barrier layer, the part having the tapering angle smaller than 90 degrees; and 
 step I of, after the step H, irradiating the condensed photocurable resin with light to form the organic barrier layer of the photocurable resin. 
 
     
     
       12. The method according to  claim 9 , further comprising:
 step F, after the step E, forming the first inorganic barrier layer selectively in an active region where the plurality of organic electroluminescent elements are formed; 
 step G of, after the step F, locating the substrate in a chamber and supplying a vapor-like or mist-like photocurable resin into the chamber; 
 step H of condensing the photocurable resin on the first inorganic barrier layer to form a liquid film; 
 step I of irradiating the liquid film of the photocurable resin with light to form a photocurable resin layer; and 
 step J of partially ashing the photocurable resin layer to form the organic barrier layer.